Unit 1 (Ch. 3,4,&5) Flashcards
Ecosystem boundaries
Some ecosystems, such as caves and lakes have very distinctive boundaries. However, in most ecosystems it difficult to determine where one ecosystems stops and the next begins.
Ecosystem
A particular location on Earth distinguished by it’s particular mix of interacting biotic and abiotic components
Ecosystem processes
Even though it is helpful to distinguish between two different ecosystems, ecosystems interact with other ecosystems.
Photosynthesis (solar energy + 6h20 +6CO2 —-> C6H12O6 + 6O2)
Producers, autotrophs are able to use the sun’s energy to produce usable energy through the process called photosynthesis (self-feeders)
Cellular respiration (energy + 6H2O + 6CO2 <—– C6H12O6 + 6O2)
Process by which other organisms gain energy from eating the tissues of producers
Consumers (heterotrophs)
Obtain energy by consuming other organisms
Primary consumers (herbivores)
Consume producers
Secondary consumers (carnivores)
Obtain their energy by eating primary consumers
Tertiary consumers (carnivores)
Eat secondary consumers
Food chain
The sequence of consumption from producers through tertiary consumers
Food web
A more realistic type of food chain that takes into account the complexity of nature
Trophic levels
Producers, PC, SC, TC, and Quatranary Consumers
Biomass
The energy in an ecosystem is measured in terms of biomass
Standing crop
The amount if biomass present in an ecosystem at a particular time
Ecological efficiency
The proportion of consumed energy that can be passed from one trophic level to another
Trophic pyramid
The representation of the distribution of biomass among trophic levels
Biosphere
The combination of all ecosystems on Earth
Biogeochemical cycles
The movement of matter within and between ecosystems involving biological, geologic, and chemical processes
The hydrologic cycle
The movement of water through the biosphere (evaporation, condensation, precipitation, runoff)
Parts of the hydrologic cycle
Transpiration- process where plants release water from their leaves into the atmosphere
Evapotranspiration- the combined amount of evaporation and transpiration
Runoff- when water moves across the land surface into streams and rivers, eventually reaching the ocean
The carbon cycle
In the atmosphere, carbon is attached to some oxygen in a gas called carbon dioxide.
Plants use carbon dioxide and sunlight to make their own food and grow. The carbon becomes part of the plant. Plants that die and are buried may turn into fossil fuels made of carbon like coal and oil over millions of years. When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide.
Carbon dioxide is a greenhouse gas and traps heat in the atmosphere. Without it and other greenhouse gases, Earth would be a frozen world. But humans have burned so much fuel that there is about 30% more carbon dioxide in the air today than there was about 150 years ago, and Earth is becoming a warmer place.
Gross primary productivity (GPP)
The total amount of solar energy that the producers in an ecosystem capture via photosynthesis over a given amount of time
Net primary productivity (NPP)
The energy captured (GPP) minus the energy respites by producers
The nitrogen cycle
Fixation - Fixation is the first step in the process of making nitrogen usable by plants. Here bacteria change nitrogen into ammonium.
Nitrification - This is the process by which ammonium gets changed into nitrates by bacteria. Nitrates are what the plants can then absorb.
Assimilation - This is how plants get nitrogen. They absorb nitrates from the soil into their roots. Then the nitrogen gets used in amino acids, nucleic acids, and chlorophyll.
Ammonification - This is part of the decaying process. When a plant or animal dies, decomposers like fungi and bacteria turn the nitrogen back into ammonium so it can reenter the nitrogen cycle.
Denitrification - Extra nitrogen in the soil gets put back out into the air. There are special bacteria that perform this task as well.
The phosphorus cycle
Over time, rain and weathering cause rocks to release phosphate ions and other minerals. This inorganic phosphate is then distributed in soils and water.
Plants take up inorganic phosphate from the soil. The plants may then be consumed by animals. Once in the plant or animal, the phosphate is incorporated into organic molecules such as DNA. When the plant or animal dies, it decays, and the organic phosphate is returned to the soil.
Within the soil, organic forms of phosphate can be made available to plants by bacteria that break down organic matter to inorganic forms of phosphorus. This process is known as mineralisation.
Phosphorus in soil can end up in waterways and eventually oceans. Once there, it can be incorporated into sediments over time.
Disturbance
An even caused by physical, chemical, or biological agents that results in changes in population size or community composition
Watershed
All of the land in a given landscape that drains into a particular stream, river, lake, or wetland
Resistance
A measure of how much a disturbance can affect it’s flows of energy and matter
Resilience
The rate at which an ecosystem returns to it’s original state after a disturbance
Restoration ecology
A new scientific discipline that is interested in restoring damaged ecosystems
The intermediate disturbance hypothesis
States that ecosystems experiencing intermediate levels of disturbance are more diverse than those with high or low disturbance levels
Provisions
Goods that humans can use directly
Regulating services
The service provided by natural systems that helps regulate environmental conditions
Support systems
The support services that natural ecosystems provide such as pollination, natural fibers, and pest control
Resilience
Resilience of an ecosystem ensures that it will continue to provide benefits to humans. This greatly depends on species diversity
Cultural services
Ecosystems provide cultural or aesthetic benefits to many people
Variations in climate determine the dominant plant growth forms of terrestrial biomes
- climate affects the distribution of species around the globe
- organisms possess distinct growth forms due to adaptations to local temperature and precipitation
Biomes
The presence of similar plant growth forms in areas possessing similar temperature and precipitation patterns
Tundra
- cold, treeless biome with low- growing vegetation. In winter, the soil is completely frozen
- the tundras growing season is very short, usually only about 4 months during summer
- the underlying subsoil, permafrost is an impermeable, permanently frozen later that prevents water from draining and roots from penetrating
Boreal forest
- forests made up primarily of coniferous (cone bearing) evergreen tress that can tolerate cold winters and short growing seasons
- boreal forests are found between about 50-60 degrees north in Europe, Russia, and North America
- this subarctic biome has a very cold climate, and plant growth is more constrained by temperature than precipitation
- the soil is nutrient poor due to slow decomposition
Temperate rainforest (Chapperal)
- moderate temperatures and high precipitation typify the temperate rainforest
- coast biome and can be found along the west coast of North America from Northern California to Alaska in southern chile on the west coast of New Zealand, and on the island of Tasmania
- ocean currents he’ll moderate temperature fluctuations and provide a source of water vapor
- this biome has a nearly 12 month growing season where winters are rainy and summers are foggy
- The mild temperatures and high precipitation supports the growth of very large trees
Temperate seasonal forest (deciduous)
- Receives over 1 m of precipitation annually
- Found in eastern United States Japan China Europe chili and eastern Australia
- dominated by broad leaf deciduous trees such as beech, male, oak and hickory
- warmer summer temperatures favor decomposition so soils generally contain more nutrients than those of boreal forests
Woodland/ Shrubland
- Found on the coast of northern California southern Australia southern Africa and in the area surrounding the Mediterranean Sea
- Hot dry summers and mild rainy winters are characteristics of this biome
- there is a 12 month growing season, but the plant growth is constrained by low precipitation in summer and by relatively low temperatures in
- wildfires are common and plants of this biome are well adapted to both fire and drought
Temperate grassland/ Cold desert
- this biome has the lowest average annual precipitation of any temperate biome
- these are found in the great plains of North America and South America and in Central Asia and eastern Europe
- Cold harsh winters and hot dry summers
- Great plains area (midwest)
- plant growth is constrained by both insufficient precipitation in summer and cold temperatures in Winter
- plants include grasses and non woody flowering plants that are well adapted to wildfires in frequent grazing by animals
Tropical rain forest
- in the tropics average annual temperatures exceed 20°C
- located 20° north and south of the equator
- found in Central and South America, Africa,southeast Asia and north eastern Australia
- precipitation occurs frequently in this biome is warm and wet with little temperature variation
- have more biodiversity per Hector than any other terrestrial biomes and contain up to two thirds of earths terrestrial species
Tropical seasonal forest/savanna
- warm temperatures and distinct wet and dry seasons
- common in central America on the Atlantic coast of South America and southern Asia and north western Australia and in sub-Saharan Africa
- lion King
- soil is fairly fertile and can be farmed due to high decomposition rates but the lower amount of precipitation constrains plant from using the soil nutrients that are released
- grasses and scattered deciduous trees are common
Subtropical desert
- found at 30° north and south with hot temperatures in extremely dry conditions
- The Mojavi desert in the southwestern United States, Sahara in Africa, the Arabian desert of the middle east and the great Victoria desert of Australia
- cacti, euphorbs, and succulent plants
Streams and rivers
- flowing freshwater that may originate from underground springs or as runoff from rain or melting snow
- streams are typically narrow and carry relatively small amounts of water where rivers are usually wider and Carry larger amounts of water
Lakes and ponds
- standing water that some of which is too deep for emergent vegetation
- Lakes are larger than ponds but there is no clear point at which a pond is considered large enough to be called a lake
Littoral zone
The shallow area of soil and water near the shore where Algae and emergent plants grow
Limnetic zone
Open water, where rooted plants can no longer survive. Phytoplankton are the only photosynthetic organisms. This zone extends to as deep as sun light can penetrate
Profundal zone
The zone where sunlight cannot penetrate and therefore producers cannot survive
Benthic zone
The muddy bottom of the lake or bond between the limnetic and profundal zone
Freshwater wetlands
- aquatic biomes that are submerged or saturated by water for at least part of each year, but shallow enough to support emergent vegetation
- these include swamps, marshes and Bogs
Salt marshes
- found along the coast in temperate climates and contains non-woody vegetation
- most productive biomes in the world
Mangrove swamps
- found along tropical and subtropical coasts and contain trees whose roots are submerged in water
- Salt tolerant and help protect the coastlines from erosion and storm damage
Intertidal zone
- narrowband of coastline that exist between the levels of high tide and low tide
- waves that crash onto the shore in this biome can make it a challenge for organisms to hold on and not get washed away
Coral reefs
- Found in warm, shallow waters beyond the shoreline
- earths most diverse marine biome even though they are found in water that is relatively poor nutrients and food
Coral bleaching
When the algae inside the coral dies. Scientist believe this is due to a combination of disease and environmental change
The open ocean
The debt that light can penetrate in the open ocean is dependent on the amount of sediment and algae suspended in the water
Photic zone
The zone that receives enough light to allow photosynthesis to occur
Aphotic zone
The deeper water that lacks sufficient light for photosynthesis
Chemosynthesis
The process that occurs in the aphotic zone where some species of bacteria use methane and hydrogen sulfide to generate energy
Weather
The short-term conditions of the atmosphere in a local area. These include temperature humidity clouds precipitation windspeed and atmospheric pressure
Climate
The average weather that occurs in a given region over a long period typically several decades
Troposphere
The layer closest to earth surface
Stratosphere
Above the troposphere
Layers of earth
Troposphere Stratosphere Mesosphere Thermosphere Exosphere and ionosphere
Unequal heating of earth
- variation in angle at which the sun’s rays strike
- amount of surface area over which the sun’s rays are distributed
- some areas of earth reflect more solar energy than others (albedo)
Water vapor capacity
Warm air has a higher capacity for water vapor than cold air
Adiabatic heating or cooling
As air rises in the atmosphere its pressure decreases and the air expands. Conversely, as air sinks, the pressure increases and the air decreases in volume
Latent heat release
When water vapor in the atmosphere condenses into liquid water and energy is released
